Aging of poly (lactic acid)/poly (butylene adipate-co-terephthalate) blends under different conditions: Environmental concerns on biodegradable plastic.

Biodegradable plastics (BPs) have been used to replace conventional plastics owing to their environmental harmless and ease of degradation. However, the aging processes of BPs in different environments remain unclear. In this study, we used poly (lactic acid)/poly (butylene adipate-co-terephthalate) (PLA/PBAT) films as model BPs and investigated the 30-d aging behavior of PLA/PBAT films under four conditions (i.e., air without ultraviolet (UV) irradiation, water without UV irradiation, air with UV irradiation, and water with UV irradiation). Our results showed that the aging of PLA/PBAT films was insignificant in all groups except the water with UV irradiation group. In the physical characterization, the PLA/PBAT films exhibited layered structures in water with UV irradiation condition, and the submicron- and nano-sized particles adhered to the bigger-sized fragments. In the chemical characterization, the carbonyl index (CI) of PLA/PBAT films in water with UV irradiation condition decreased from 3.84 to 1.36, and the oxygen-to-carbon (O/C) ratio reached a maximum of 1.78 at 20 d and declined to 0.49 at 30 d, indicating that the oxygen-containing functional groups underwent bond breaking and showed a rapid aging process. This is mainly attributed to the combined effect of hydrolysis and photolysis increases the contact area of PLA/PBAT films and accelerates the aging process. Furthermore, based on two-dimensional correlation spectroscopy (2D-COS) analysis, we suggest that free radicals generated in water with UV irradiation conditions also accelerate the aging process of PLA/PBAT films. This study explored the aging processes of PLA/PBAT films under different conditions, which could aid in clarifying the environmental behavior and provide further information to assess the potential risks of BPs.

Pharmaceuticals and Personal Care Products across Different Water Bodies in Taihu Lake Basin, China: Occurrence, Source, and Flux.

Although pharmaceuticals and personal care products (PPCPs) have attracted great attentions, their occurrence characteristics across different water bodies at a basin scale remain poorly understood. To grasp a more comprehensive understanding of PPCP pollution from the perspective of the whole basin, the occurrence, spatial and seasonal variation, source, and flux of thirteen PPCPs across the different environmental compartments of the northern Taihu Lake Basin (TLB) were studied. The results showed that the non-therapeutic pharmaceuticals caffeine (CFI) and n, n-diethyl-m-toluamide (DEET) were the main components across the different environmental compartments. The total concentrations of detected PPCPs ranged from 0.2 to 2437.9 ng/L. Higher concentrations of PPCPs were observed in spring and autumn, which were mainly attributed to seasonal differences in PPCP consumption. Generally, pollution level was higher in industry and agriculture area and in the inner bay and southwest of Taihu Lake. Source apportionment indicated that untreated water was the main source of PPCPs in river waters of the northern TLB. Flux estimation showed that the mean annual flux of PPCPs from northern TLB to Taihu Lake in 2021 was 1.6 t/a, which was higher in comparison with other areas. Overall, the resulting data will be useful to enrich the research of PPCPs in freshwater for environmental investigations.

Sorption of selected pharmaceutical compounds on polyethylene microplastics: Roles of pH, aging, and competitive sorption.

Microplastics (MPs) as the carrier of pharmaceuticals in aquatic environments have been concerned in recent years. However, the influences of environmental factors on the sorption of pharmaceuticals onto MPs, particularly the effect of the simultaneous sorption by MPs of different pharmaceuticals in multi-solute systems are still unclear. This study investigated the influences of pH, aging of MPs, and competition of pharmaceuticals on the sorptions of sulfamethoxazole (SMX), propranolol (PRP), and sertraline (SER) onto polyethylene MPs. In the 96 h pH-dependent experiments, the sorptions of the three pharmaceuticals were mainly driven by hydrophobic interaction. Besides, the ionization states of the three pharmaceuticals varied with the pH ranging from 2.00 to 12.00, and electrostatic interaction would affect the sorption affinities of the pharmaceuticals in different ionization states. In the aged MPs experiments, the MPs aged by UV irradiation showed a stronger sorption capacity than the pristine ones. Across the MPs under different UV irradiation durations, the 6 d aged MPs showed the highest sorption percentages of 23.0% and 17.6% for SER and PRP, respectively; for SMX, the highest sorption percentage of 5.4% was recorded with the 10 d aged MPs. In the multi-solute systems, the sorption kinetics of the three pharmaceuticals fit well with the pseudo-second-order model. The sorption quantities of the three pharmaceuticals onto MPs followed the order of SER cations (18.70 µg g-1) > SMX anions (7.83 µg g-1) > PRP cations (3.80 µg g-1) at pH 7.00. The good fitting of the Freundlich model suggested a multilayer sorption of the three pharmaceuticals onto MPs. The SER with higher hydrophobicity would preferentially be adsorbed onto MPs and influenced the subsequently sorption processes of the other pharmaceuticals via electrostatic interactions. This may change the environmental fate of the contaminants, which should be carefully considered in future work.

Abnormally High Blood Acetaldehyde Concentrations Suggest Potential Postmortem Ethanol Generation.

Ethanol is one of the most commonly used and abused substances worldwide. Identifying whether the source of ethanol detected in corpses is antemortem ingestion or postmortem generation is especially important for determining the cause of death, which remains a vibrant field of research. During the synthesis of ethanol in the putrefaction process of corpses, other small molecules such as acetaldehyde and n-propanol could also be produced. According to our prospective statistical analysis based on authentic samples from forensic cases, it is rational to suspect ethanol generation after death when the concentration of acetaldehyde detected in blood exceeds 0.014 g/dL. Through in vitro simulation experiments, in addition to confirming that ethyl glucuronide and ethyl sulfate are the reliable biomarkers of antemortem ingestion of ethanol, we propose that acetaldehyde is far more sensitive than n-propanol as a potential marker in the blood of corpses for postmortem ethanol formation.

Surrogate analyte-based quantification of main endocannabinoids in whole blood using liquid chromatography-tandem mass spectrometry.

Endocannabinoids (eCBs) are endogenous ligands of the endocannabinoid system that are known to regulate several physiological and behavioral processes. Previous studies have developed methods for the detection of main eCBs including arachidonylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), mostly in serum or plasma. Whole blood is a superior biomaterial for eCBs analysis owing to the nature of the shortened isolation procedure and decreased risk of 2-AG isomerization during preparation. In this study, a surrogate analyte-based liquid chromatography-tandem mass spectrometry assay was developed for the measurement of AEA, 2-AG and its isomer 1-arachidonoylglycerol (1-AG) using a maximum of 100 µL whole blood. Chromatographic separation was achieved using a reverse-phase column and a gradient elution. Detection was performed in selected reaction monitoring mode with an electrospray ionization source. The limits of detection of three eCBs were 0.05-0.1 ng/mL. Good linearity was observed over the concentration range. Intra- and inter-assay accuracy and precision were ≤10.9 and ≤8.7% at four quality control levels. The response factor and parallelism experiment illustrated that the surrogate analytes were suitable for accurate quantification of the main eCBs in whole blood. This surrogate analyte approach was successfully applied to authentic blood samples obtained from alcohol negative drivers and those under the influence of alcohol.

Simultaneous determination of major phytocannabinoids, their main metabolites, and common synthetic cannabinoids in urine samples by LC-MS/MS.

Simultaneous determination of major phytocannabinoids (THC, CBD, CBN), their main metabolites (11-OH-THC, THC-COOH, THC-COOH-glucuronide) and common synthetic cannabinoids (HU-210, JWH-018, JWH-073, JWH-250) remains an issue in forensic toxicology. The present study has developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to simultaneously detect the above 10 analytes in human urine samples. The chromatographic separation was performed on an ACQUITY UPLC(®)BEH Phenyl 1.7µm (2.1×100mm) column, using a mobile phase consisting of 0.1% formic acid in water and acetonitrile at a flow rate of 0.3mL/min in gradient elution mode. The limit of detection (LOD) and limit of quantification (LOQ) of all analytes were 0.01-0.5ng/mL and 0.05-1ng/mL, respectively. The assay was linear from LOQ to 100ng/mL for phytocannabinoids, their main metabolites and HU-210, and from 0.05 to 50ng/mL for JWH-250, JWH-018 and JWH-073. The extraction recoveries were over 50% and the matrix effects were between 59.4% and 100.1%. The accuracy and precision were <10.4% of bias and <10.5% of relative standard deviation (RSD), respectively. The developed method was applied to 5 urine samples from real caseworks, and the results that THC metabolites together with synthetic cannabinoids were detected demonstrated the effectiveness of our method.

[Effects of applying controlled release fertilizers on N2O emission from a lateritic red soil].

Static closed chamber technique and contrast method were adopted to study the effects of three coated compound fertilizers (N:P2O5:K2O = 19:8.6:10.5, high N; 14.4:14.4:14.4, balanced NPK; and 12.5:9.6:20.2, high K) on the NO2O emission from a lateritic red soil under the condition of no crop planting, taking uncoated compound fertilizers (N:P2O5:K2O = 20:9:11, high N; 15:15:15, balanced NPK; and 13:10:21, high K) as the contrasts. Different formula of fertilizer NPK induced significant difference in the N2O emission. Under the application of uncoated compound fertilizers, the cumulative N2O emission was in the order of balanced NPK > or = high N > high K. Applying coated compound fertilizers decreased the N2O emission significantly, and the emission amount under the application of high N, balanced NPK, and high K was 34.4%, 30.5%, and 89.3% of the corresponding uncoated compound fertilizers, respectively. Comparing with the application of uncoated compound fertilizers, applying coated compound fertilizers also decreased the daily N2O flux significantly, and delayed and shortened the N2O peak, suggesting that coated fertilizers could reduce soil nitrogen loss and the global warming potential induced by N2O emission.

[Detecting the concentrations of bisphenol A (BPA) in air of workplaces with HPLC].

OBJECTIVE: To establish the method of detecting the concentrations of bisphenol A (BPA)in air of workplaces with high performance liquid chromatographic (HPLC). METHODS: According to standards of methods for determining the chemical substances in workplace air, BPA in the air was collected by glass fiber filter, then dissolved by acetonitrile and determined by high performance liquid chromatography with FLD. RESULTS: There was a linear relationship within the range of 0.01-10.0 pg /ml, and the detection limit was 0.005 pg/ml. The lowest detected concentration was 3.3x10-5 mg/m3. The relative standard deviation was 2.5-5.5%. The dissolution efficiencies were 95.0%-101.9% and the sampling efficiencies were 99.6%. The samples in glass fiber filter membrane could be stored for 7 days at room temperature. CONCLUSION: The present method could meet with the requirements of Guide for establishing occupational health standards-Part 4 Determination methods of air chemicals in workplace and be feasible for determination of BPA in workplace air.

GC-FPD measurement of urinary dialkylphosphate metabolites of organophosphorous pesticides as pentafluorobenzyl derivatives in occupationally exposed workers and in a general population in Shanghai (China).

Measurement of organophosphorus (OP) pesticide metabolites in human biological fluids is an important biomarker of pesticides exposure. We measured the urinary excretion of OP pesticide metabolites to evaluate occupational and non-occupational exposure to OP pesticides in the Chinese population in Shanghai (Eastern China). We collected urine samples from 30 exposed workers in a dimethoate emulsion packing division and from 60 healthy adults without any report of occupational exposure. DMP, DMTP, DMDTP, DEP, DEDP and DEDTP were measured by GC-FPD after derivatization with pentafluorobenzyl bromide. The LOQ values (1 mL urine) were 2.0 µg/L for DMP and DETP, 4.0 µg/L for DEP and DEDTP, 8.0 µg/L for DMDTP, and 10.0 µg/L for DMTP. Dimethyl phosphates were detected in the majority of the urine samples, i.e., 90-100% in the exposed group and 80-87% in the control group. The concentration of the urinary diethyl phosphates DEP and DETP was above the LOQ values in 40 and 20% of samples for the exposed group, and in 50 and 30% of the samples for the control group, respectively. DEDTP was not detectable in the urine samples except for a post-shift exposed worker (detection frequency, 6.7%). Median creatinine-adjusted values (µg/gcr.) for DAP in Chinese with pre-shift, post-shift and without occupational exposure to OP were 316, 584 and 170 for DMP, below LOQ, 115 and 114 for DEP, 840, 1730 and 693 for DMTP, and 255, 756 and 135 for DMDTP, respectively. In all subjects, the highest excretion levels were found for DMTP. Several OP pesticide metabolites were frequently detected in urine samples of both populations studied.

[Study on the levels of the bisphenol A, octylphenol, 4-nonylphenol in serum of precocious girls].

OBJECTIVE: To investigate the role of bisphenol A (BPA), octylphenol (OP), 4-nonylphenol(4-NP) causing precocious girls. METHODS: The blood samples were collected from 110 cases of precocious girls and 100 cases of normal girls. The concentrations of BPA, OP, 4-NP in serum samples were measured by using high performance liquid chromatography (HPLC), the volume of the uteruse and ovary, the content of estradiol (E2) were determined at the same time. The contents of BPA, OP, 4-NP in blood serum of precocious girls and the indices of the target organs were analyed by using correlation. RESULTS: BPA and, OP were detected in blood serum for 40.9% and 33.6% of precocious girls respectively, BPA and OP were detected for only 2% and 5% in normal girls respectively, 4-NP was detected for 24.54% of precocious girls and 3% of normal girls. The ratio of BPA, OP, 4-NP in blood serum of precocious girls was higher than normal girls respectively (P < 0.01), BPA in blood serum of precocious girls patients was positive correlation with the volume of the uterus (r = 0.557, P < 0.05), and positive correlation with volume of the ovary (r = 0.469, P < 0.01). OP in blood serum of precocious girls patients was positive correlation with the volume of uterus (r = 0.576, P < 0.05), positive correlation with volume of ovary (r = 0.676, P < 0.01). CONCLUSION: Precocious girls patients were contaminated more severely than normal girls, and BPA, OP could influence the volume of the uterus and ovary, so it had some relationship with cause of precocious girls.

Expression of Cre recombinase in retinal Müller cells.

PURPOSE: In an effort to generate inducible RPE-specific Cre mice using a 3.0-kb human vitelliform macular dystrophy-2 (VMD2) promoter, we identified a mouse line with unanticipated Cre activity in the neural retina, including Müller glial cells. Müller cells play important roles in the function and maintenance of the retina, and this mouse line would be potentially useful for conditional gene targeting in Müller glia. We therefore characterized the timing, inducibility, and cell specificity of Cre expression, as well as Müller cell-specific efficiency of Cre-mediated recombination in this mouse line. METHODS: Transgenic mice carrying cassettes of human P(VMD2)-rtTA and TRE-cre were generated. Cre expression was characterized using a Cre-activatable lacZ reporter mouse line (R26R) and a floxed interleukin six signal transducing receptor (gp130) mouse line. RESULTS: beta-Galactosidase (beta-gal) assay and immunohistochemical analysis of VMD2-cre/R26R double transgenic mice indicated that Cre activity was detected in cells located in the inner nuclear layer, with prominent expression of beta-gal in Müller cells. Cre activity was also detected in photoreceptors in the outer nuclear layer. PCR analysis demonstrated that Cre-mediated recombination initiated by embryonic day 15. Immunohistochemical analysis indicated that Cre-mediated deletion of floxed gp130 gene occurred in 52% of the retinal Müller cells. Retinal function and morphology were normal in 10-month-old VMD2-cre mice. CONCLUSION: We generated a transgenic cre mouse that is useful to study gene activation and inactivation in retinal Müller cells.

Electroacupuncture at Qiuxu (GB 40) for treatment of migraine--a clinical multicentral random controlled study.

OBJECTIVE: To observe the therapeutic effects of electroacupuncture (EA) at Qiuxu (GB 40) for treatment of migraine so as to provide clinical evidence for compilation of the Acupoints' Dictionary of the People's Republic of China. METHODS: 275 migraine patients admitted in 3 hospitals were randomly divided into a treatment group treated by EA at Qiuxu (GB 40), and a control group treated by EA at Tianshu (ST 25). The indexes of the migraine symptoms and the 5-HT level were observed in both the groups before and after treatment. RESULTS: There was a significant difference in VAS score between the two groups of the 3 clinical centers (P<0.01). The therapeutic effects of a 4-week treatment were much better in the treatment group than that of the control group. The 3-month follow-up survey showed that the long-term effects were in favor of the treatment group of the first and third clinical centers, though no significant difference was found in the treatment group of the second clinical center as compared with the control group. The results from the 6-month follow-up survey showed better effects in the treatment group of all the 3 clinical centers. CONCLUSION: EA at Qiuxu (GB 40) may show effect for migraine.

Phthalate levels and low birth weight: a nested case-control study of Chinese newborns.

OBJECTIVE: To assess maternal-fetal exposure to phthalates and investigate whether in utero phthalate exposure is associated with low birth weight (LBW). STUDY DESIGN: A total of 201 newborn-mother pairs (88 LBW cases and 113 controls) residing in Shanghai were enrolled in this nested case-control study during 2005-2006. Maternal blood, cord blood, and meconium specimens were collected and analyzed for phthalates by high-performance liquid chromatography-mass spectrometry. Nonparametric tests were used to compare demographic characteristics in cases and controls. Conditional logistic regression and Spearman correlation were used to analyze the association between phthalate exposure and LBW. RESULTS: No significant differences in gestational age, prepregnancy body mass index, prenatal care, vitamin supplementation, or socioeconomic levels were found between the LBW and control infants. More than 70% of the biosamples had quantifiable levels of phthalates, with higher levels in the LBW infants compared with the controls. Prenatal di-n-butyl phthalate (DBP) exposure was associated with LBW, and di-2-ethylhexyl phthalate (DEHP) was negatively associated with birth length. After adjusting for the potential confounders, DBP concentrations in the highest quartile were associated with an increased risk of LBW. CONCLUSIONS: Newborns in China are ubiquitously exposed to phthalates; significantly higher phthalate levels were detected in LBW cases compared with controls. In utero DBP and DEHP exposures were associated with LBW in a dose-dependent manner. Prenatal phthalate exposure may be a risk factor for LBW.

[Levels of environmental endocrine disruptors in umbilical cord blood and maternal blood of low-birth-weight infants].

OBJECTIVE: To monitor the biological levels of environmental endocrine disruptors (EDs, phthalates and surfactants) in the umbilical cord blood and maternal blood of low-birth-weight infants. METHODS: All 30 umbilical cord blood samples and 21 maternal blood samples were collected from low-birth-weight infants. The concentration of four kinds of phthalates (di-2-ethylhexyl phthalate, DEHP; mono-2-ethylhexyl phthalate, MEHP; di-ethyl phthalate, DEP; di-n-butyl phthalate, DBP) and two kinds of surfactants (4-nonylphenol, 4-NP; octylphenol, OP) in these blood samples were measured by using reversed-phase high performance liquid chromatography. RESULTS: The mean birth weight and birth length of low-birth-weight infants were (2158.48 +/- 125.06) g and (45.36 +/- 2.52) cm, respectively. The concentrations of DEP, MEHP, DBP, DEHP, 4-NP and OP were 18.90, 11.87, 7.67, 8.84, 1.51 and 2. 86 mg/L in maternal blood, and the detective rates were 86.7%, 63.3%, 60.0%, 63.3%, 56.7% and 66.7%, respectively. In umbilical cord blood, the concentrations of those EDs were 11.92, 9.94, 5.71, 5.20, 1.12 and 1.19 mg/L; the detective rates were 86.7%, 63.3%, 60.0%, 63.3%, 56.7% and 66.7%. No matter in maternal blood or in umbilical cord blood, the contents and detective rates of phthalates were higher than the surfactants. The concentration of MEHP was higher than its primer, DEHP. The contents of the target EDs in umbilical cord blood were less than those in the matched maternal blood. The percentages were 47.82% -84.05%. CONCLUSION: People could be exposed to EDs from embryo period. And this should be paid attention by the related departments.

[Evaluation of two-year follow-up of group intervention on smoking cessation based on social cognitive theory].

OBJECTIVE: To assess the effect of a group intervention on smoking cessation based on social cognitive theory. METHODS: A total of 217 smokers were recruited through mobilization in the community. Six-month and 2-year follow-up surveys were engaged after intervention to evaluate the effectiveness of the training. RESULTS: Smoking quitting rate confirmed by biomarker level in the 2-year follow-up survey could achieve 32.3% and the successful quitting rate could be 15.2%. The factors influencing smoking cessation at 2-year follow-up could be associated with diseases related to smoking (AOR = 4.09), the change in self-efficacy scores (AOR: 1.05-1.13) and home smoke-free policy (AOR= 5.07). CONCLUSION: The group intervention on smoking cessation based on social cognitive theory could be effective and can be used in community.

Inducible expression of cre recombinase in the retinal pigmented epithelium.

PURPOSE: The retinal pigmented epithelium (RPE) expresses many genes that play important roles in the support and maintenance of photoreceptors. The present study was conducted to develop a system amenable to the dissection of the temporal function of these genes, specifically within RPE cells. Transgenic mice were generated and characterized in which the expression of Cre recombinase could be specifically induced within the RPE. METHODS: Transgenic mice carrying the human vitelliform macular dystrophy-2 (VMD2) promoter (P(VMD2))-directed reverse tetracycline-dependent transactivator (rtTA) and the tetracycline-responsive element (TRE)-directed cre were generated. Inducible Cre expression was achieved by feeding doxycycline to these mice and was characterized by using a Cre-activatable lacZ reporter mouse strain (R26R). RESULTS: A beta-galactosidase assay of rtTA/Cre-R26R mice demonstrated that the basal level of Cre expression without doxycycline induction was negligible. Addition of doxycycline led to induction of RPE-specific Cre expression/function at least from embryonic day 9 to postnatal day 60. The highest induction occurred at approximately postnatal day 4. As measured by ERG and histology, retinal function and morphology were normal in 10-month-old rtTA/Cre mice that were treated with doxycycline at weaning age. CONCLUSIONS: Transgenic mice were generated that express Cre recombinase in the RPE in an inducible fashion. These mice will be useful for studies of the RPE-specific role of genes that are expressed in the RPE as well as other cells, particularly for avoiding embryonic lethality and dissecting the function of genes that play dual roles in development and adulthood.

[Study on the therapeutic effect of electroacupuncture on migraine and influencing factors].

OBJECTIVE: To compare therapeutic effects of electrical acupuncture (EA) at Qiuxu (GB 40) and Tianshu (ST 25), and to probe the factors of influencing the therapeutic effect. METHODS: Two hundred and seventy-five cases were randomly divided into the test group of 138 cases treated with EA at Qiuxu (GB 40) and the control group of 137 cases treated with EA at Tianshu (ST 25). Their therapeutic effects were observed and the factors influencing the therapeutic effect were analyzed. RESULTS: The transient effective rate was 70.3% in the test group and 58.4% in the control group with a significant difference between the two groups (P<0.05), and there were very significant differences between the two groups in the therapeutic effects at treatment of 4 weeks, and following-up 3 and 6 months later (P<0.001), the transient analgesic effect of EA at Qiuxu (GB 40) being better. EA had better transient effect on migraine for the mental workers, or the patient with high pain score at treatment, or more frequent attack. The long-term analgesic effect of EA at Qiuxu (GB 40) was better than Tianshu (ST 25). CONCLUSION: The analgesic effect of EA at Qiuxu (GB 40) is better than Tianshu (ST 25) and the profession and conditions of the patient are the factors influencing the therapeutic effect.